Synthetic lubricant



Patentec! June 8, 1948 SYNTHETIC LUBRICANT Orland M. Reiff, Woodbury,Howard D. Hartough, Pitman, and Harry J. Andress, Jr., Woodbury, N. J.,assignors to Socony-Vaeuum Oil Company, Incorporated, a corporation ofNew York No Drawing. Application J one 13, 1944, Serial No. 540,145

14 Claims. 1

This invention has to do with the art of lubrication and, moreparticularly. has mm with the preparation of synthetic lubricants.

In the lubricant art, considerable progress has been realized in recentyears in the production of lubricants characterized by one or more spe-I clfic properties and adapted for particular uses. In the main, thisprogress can be attributed to two developments: the first, new refiningprocedures and, the second, addition agents capable of impartingparticular properties to available lubricants. Although these lubricantsare somewhat superior to those formerly available in the art, ingeneral, they too suffer in one or more respects. For example, whilesuch oils may have superior viscosity characteristics, etc., they mayhave undesirable oxidation characteristics, etc. Recently, however, inan effort to obtain superior lubricants endowed with specific andsuperior characteristics, a new field has been explored, namely, thesynthesis 'of lubricants from various materials. The products soobtained have been aptly described in the art as synthetic lubricants.

While many of the synthetic lubricants recently prepared have been foundto be desirable for various uses in view of a superi r characteristicsuch as improved oiliness, viscosity, resistance to oxidation, etc.,they invariably have extremely high pour points which naturally militateagainst their wide use in the art. Generally, they suffer too from thedisadvantage of a failure to respond to pour point depressants when thelatter are incorporated therewith in relatively small amounts.

The present invention is predicated upon the discovery of a new andnovel class of synthetic lubricants-paraflln wax xylenes-which arecharacterized by relatively low pour points and which are responsive tosubstantial Pour point depression upon the addition thereto of smallamounts of a novel class of pour point depressants, the esters ofalkyl-substituted phenols. The synthetic lubricants of this invention,in combination with the said pour point depressants, are allcharacterized by pour points of F. (A. S. T. M.) and are furthercharacterized by outstanding viscosity index values and resistance tooxidation.

Also contemplated herein is a method for the preparation of the said newand novel synthetic lubricants, the method involving reacting certainpartially halogenated paramn waxes with xylene in the presence of aFriedel-Crafts catalyst at a condensation temperature and thereafterseparating the catalyst and. any unchanged reactants from the reactionmixture so obtained. While the present method may be briefly summarizedby the foregoing statement, it is much more complex than as so stated,inasmuch as several of the factors recited therein are critical innature and must be followed religiously lest products of a somewhatinferior character be formed. Specifically, the several criticalfactors, all of which are interrelated, include the following:

1. Type of parafiln wax,

2. Degree of halogenation of the paraffin wax and 3. Proportions ofhalogenated paraffin wax and of a xylene.

Of importance in the present method is the type of parafiin wax used. Wehave found that when a crystalline parafiln wax having a melting pointnot greater than about 140 F. is used, synthetic lubricants ofrelatively low pour point and susceptible to pour point depression areobtained. Particularly preferred waxes of this type, however, are thosehaving melting points from about F. to about F. These waxes have acrystalline structure, as opposed to other paraflin waxes which donothave a, well-defined crystal structure and are amorphous incharacter, The latter are commonly referred to as amorphous waxes, andare considered to be undesirable for the purposes of this invention, forsuch waxes would result in products having relatively high meltingpoints and having comparatively little susceptibility to pour pointdepression. Of the pression wax unless otherwise qualified denotes thedesired reactant: crystalline paraflln wax.

With regard to the degree of halogenation of wax which must be followed,it may first be said that all halogens may be used. In view of therelative cost, availability, etc., however, chlorine is preferred and,for this reason, the following description will be confined to thechlorinated.

waxes. It is essential that the chlorinated waxes reacted with a xylenecontain from about 21 per cent to about 24 per cent chlorine. When chlo--rine concentrations in excess of the maxima. about 24 per cent, areused, the products obtained therefrom are characterized by relativelyhigh viscosities and do not have sufiiciently low pour points- F. whensmall amounts of the aforesaid pour point depressants are incorporatedtherewith. Similarly. when chlorine concentrations lower than about 21per cent are used. the products so obtained contain excessive amounts ofwax and have undesirably high pour points, above 0 F.

It should be understood that a 21 per cent chlorinated wax is oneprepared by introducing chlorine into a crystalline paraflin wax, asdefined above, until the weight of the wax has increased about 21 percent. Such a product is predominantly comprised of dichlorinated waxwith substantial quantities of unchlorinated wax, monochlorowax and morehighly chlorinated wax. It should also be understood that when otherhalogens are used in place of chlorine in the wax reactant, theforegoing percentage range from about 21 per cent to about 24 per cent,will be subject to change in proportion to the relative atomic weightsor the individual halogens.

Of primary importance are the relative amounts or proportions of thereactants, namely, chlorinated wax and a xylene. In order to obtain thedesired product, at least one mole of a xylene is reacted with an amountof chlorinated wax which contains one atomic weight oi. chlorine. Inshort, at least one mole of a xylene is used for each atomic weight ofchlorine in the chlorinated wax reactant. Accordingly, it will be clearthat the reaction products obtained with such proportions arepredominantly monowax xylenes. If less than one mole of a xylene is usedfor each atomic weight of chlorine in a chlorowax, products of lessdesirable character are obtained. The latter products,

unlike those contemplated herein, sufier from their failure to give pourpoints of 0 F. or lower when small amounts of the aforesaid pour pointdepressants are used therewith.

The reaction temperatures useful in the present method are thosenormally referred to in the art as Friedel-Crafts condensationtemperatures. While temperatures from about 25 C. to about 145 C. may beused satisfactorily, the preferred reaction temperatures are about135-145 C., the boiling points of xylenes.

The amount of catalyst used in the condensation should be relativelysmall, that is, a catalytic amount. Generally, amounts from about 1 percent to about per cent by weight of the chlorowax reactant aresatisfactory, and amounts of the order of 3 per cent are preferred.Catalysts such as aluminum chloride, zinc chloride. ferric chloride,boron trifiuoride, hydrogen fluoride, etc., serve the purpose of thisinvention: and for this reason. the catalysts are defined broadly hereinas those capable of effecting a Friedel-Crafts type condensation.Particularly preferred, however, is aluminum chloride.

In order to more fully illustrate the method by which our syntheticlubricants are obtained.

the following typical procedure is detailed hereinbelow.

EXAMPIE.

PRIPARATIOII OI WAX-Km (1-21) Two moles of xylene (212 grams) and 170grams of a 21 per cent chlorowax (126 F. A. S. T. M. melting point) areplaced in a flask equipped with a thermometer. reflux condenser and anelectains 1 atomic weight of chlorine. Aluminum chloride (5 grams) isslowly added to the chlorowax and xylene at a temperature of about 25'C. while agitating the same. The temperature is then raised to thereflux temperature of the xylene-about C.and maintained for about 1 hourto complete the condensation of chlorowax and xylene. The reactionmixture is then purified by filtering through a contact clay to removealuminum chloride. The filtrate is then heated to remove excess xyleneand the residue obtained thereby is a wax-substituted xylene containingsome unreacted wax about 5 to 15 per cent unreacted wax. The unreactedwax is removed by vacuum distillation (it may also be removed byconventional dewaxing procedures). The product is wax-xylene (1-21).

Parenthetical, expressions (1-21) indicating that xylene is substitutedwith 1 wax group and that the chlorowax used in the preparation thereofcontained 21 per cent chlorine are used hereinafter to so identify eachproduct illustrative of the present invention, as well as relatedproducts which do not possess the superior characteristics of thelubricants prepared as outlined above.

It will be understood, of course, that any unreacted xylene can be usedagain in the preparation of additional product, and that unreacted waxcan be further chlorinated for future use.

Although we have illustrated our synthetic lubricants by a product freeof unreacted wax (removed by vacuum distillation. solvent dewaxing,etc.) it is to be understood that it is not essential that all of theunreacted wax be removed. Accordingly, both wax-free syntheticlubricants and synthetic lubricants containing relatively small amountsof unreacted wax are contemplated herein.

In order to illustrate the superior characteristics of the syntheticlubricants of the present invention, several typical examples arepresented hereinbelow in Table I. There, the S. U. V. at 210 F.,viscosity index and A. S. T. M. pour test of the above syntheticlubricants are shown; all of these characteristics and methods fordetermining the same are well known and need not be further described atthis point. In addition, the response of these synthetic lubricants withand without a pour point depressant is also demonstrated. Also presentin Table I for comparison with the synthetic lubricants contemplatedherein are several typical products which are much less desirable foruse as lubricants for one reason or another. For convenience inidentifying the lat- ;ezblproducts, they are preceded by an "X" in 1A-pour depressant: tetra-wax phenol phthalate.

It will be clear on inspection of the pour test results set forth inTable I that wax-xylenes prepared i'rom a chlorowax containing 12. 2'!and 28 per cent chlorine do not give pour points of 0 1?. and lower whena small amount of pour depressant A is incorporated therein.Surpristrically driven stirrer. The chlorowax used eon- 1| insly.however, when the chlorowax reactant con- To illustrate the criticalnature or the proportions of xylene and of the halogen wax reactants inobtaining the synthetic lubricants o! thislnvention, and those relatedmaterials of somewhat interior character, several typical examples ofwax-xylenes are shown in Table III below. The data in this table aresimilar to those shown in Table I above and the products notcontemplated herein are again identified by the letter K which precedesthem, as 'X wax-xylene Table II A. 8. '1. M. A. S. T. M Product 5- v.1.Pom- Test, ggm

F. A l

Wax-xylene 51-21).-- 63. 6 89. 5 +2) & Wax-xylene l-24)--- 75.4 75.5 +2)5 X wax-xylene iii-2i)- 53.7 110.9 +2) +2] X wax-xylene 3-24)- 55.8110.1 +20 +fi) l A==pour depressant: tetra-wax phenol pbthalate.

It will be seen that wax-xylenes (1-21) and (l-24) in Table II have pourpoints of less than 0 F. with pour point depressant A. Yet. waxrwlenesprepared with chlorowaxes containing 'the same percentages (21 and 24)of chlorine as those used in the preparation of the aforesaid monowaxsynthetic lubricants, but prepared with more than one mole of a xylenefor each atomic weight of chlorine in the chlorowax are not so favorablycharacterized.

In Tables I and II above. tetra-wax phenol phthalate-which ispreferred-is used to illustrate the class of pour point depressantscontemplated herein. it is to be understood. however, that all esters ofalkyl-substituted phenols, particularly those in which the alkylsubstituent is parafiin wax, are broadly contemplated. Such depressantsare described in detail in Patent Nos. 2,048,465 and 2,048,466 issued to0. M. Reid et 2.1. Although varying amounts of these materials may beused herein, satisfactory results are obtained with concentrations offrom about 0.125 per cent to about 1.0 per cent.

We claim:

1. A lubricant of low pour point comprising a synthetic lubricant havingincorporated therewith a small amount, sufilcient to characterize thesaidlubricant with a pour point at least as low as 0 F., of an ester ofan alkyi-substituted phenol, said synthetic lubricant being preparedfrom a crystalline paramn wax having a melting point not greater thanabout 140 F. and a xylene by: partially halogenating the paraflln wax toform a mixture of halogenated wax and substantially unhalogenated waxcontaining an amount of halogen corresponding to from about 21 per centto about 24 per cent chlorine; mixing the halogenated wax andunhalogenated wax with said xylene in the proportion of at least onemole of xylene to each atom of halogen in the halogenated wax mixture;adding thereto a catalyst capable of efiecting a. Friedel-Crafts typecondensation;

heating the mixture thus obtained at a Friedel- Craits condensationtemperature until substan-.

tially all of the halogenated wax has reacted with said xylene; andseparating the Friedel-Crafts catalyst, unreacted xylene andunbalogenated wax from the reaction mixture so obtained, to obtain saidsynthetic lubricant- 2. A lubricant of low pour point comprising asynthetic lubricant having incorporated there! within small amount,suillcient to characterize the said lubricant with a pour point at leastasiow as 0 E, of an ester of an aikyl-substituted phenol, said syntheticlubricant being prepared from a crystalline parailin wax having a.melting point not greater than about 140 F. and a xylene by: partiallychlorinating the paraflln waxto form a mixture oi chlorinated wax andunchlorinated wax containing from about 21 per cent to about 24 per centchlorine; mixing the chlorinated wax and unchlorinated wax with saidxylene in the proportion of at least one mole of xylene to each atom ofchlorine in the chlorinated wax mixture: adding a Friedel-Craitscatalyst thereto; heating the mixture thus obtained under refluxingcondi tions to the refluxing temperature of said xylene untilsubstantially all of the chlorinated wax has reacted with said xylene;and separating the Friedel-Crafts cataLvst, unreacted xylene andunchlorinated wax from the reaction mixture so obtained, to obtain saidsynthetic lubricant.

3. A lubricant of low pour point comprising a synthetic lubricant havingincorporated therewith a small amount, sufllcient to characterize thesaid lubricant with a pour point at least as low as 0 E, of an ester ofan alkyl-substituted phenol, said synthetic lubricant being preparedfrom a crystalline paraflln wax having a melting point between about F.and about F., and a xylene by: pactially chlorinating the parafiln waxto form a mixture of chlorinated wax and unchlorinated wax containingfrom about 21 per cent to about 24 per cent chlorine; mixing thechlorinated wax and unchlorinated wax with said xylene in the proportionof at least one mole of xylene to each atom of chlorine in thechlorinated wax mixture; adding a Friedel crafts catalyst thereto;heating the mixture thus obtained under refluxing conditions to therefluxing temperature of said xylene until substantially all of thechlorinated wax has reacted with said xylene; and separating theFriedel-Crafts catalyst, unreacted xylene and uncblorinated wax from thereaction mixture so obtained, to obtain said synthetic lubricant.

4. A lubricant of low pour point comprising a synthetic lubricant havingincorporated there with a small amount, sufii'cient to characterize thesaid lubricant with a pour point at least as low as 0 F., of an ester ofan alkyi-substituted phenol,- said synthetic lubricant being preparedfrom a crystalline paraflin wax having an average of about 24 carbonatoms and a melting point of about 126 and a xylene by: partiallychlorinating the parafiln wax to form a mixture of chlorinated wax andunchlorinated wax containing from about 21 per cent to about 24 per centchlorine; mixing the chlorinated wax and tumblerinated wax with saidxylene in the proportion of at least one mole of xylene to each atom of7 Priedel-Craits catalyst, unreacted xylene and unchlorinated wax mm thereaction mixture so obtained, to obtain said synthetic lubricant.

5. A lubricant of low pour point comprising a synthetic lubricant havinincorporated therewithasmallamounhsufllcienttocharacterlne the saidlubricant with a pour point at least as low as '0' F., or an ester andbl-substituted phenol. said synthetic lubricant being pr par from acrystalline paraflin wax having a melting point not greater than about140 1". and a xylene by: partially chlorinatin'g the paraiiln wax toform a mixture of chlorinated wax and unablerinated wax containing fromabout 21 per cent to about 24 per cent chlorine: mixing the chlorinatedwax and unchlorinated wax with said xylene in the proportion of at leastone mole ofxylene to each atom of chlorine in the chlorinated waxmixture; adding a catalytic amount oi aluminum chloride thereto: heatingthe mixture thus obtained imder refluxing conditions to the refluxingtemperature of said xylene until substantially all or the chlorinatedwax has reacted with said xylene; and separating the aluminum chlorine,unreacted xylene and unchlorinated wax from the reaction mixture soobtained,to obtain said synthetic lubricant.

6. A lubricant of low pour point comprising a synthetic lubricant havingincorporated therewith a small amount, sufllcient to characterize thesame lubricant with a pour point at least as low as 0 R, of an ester ofan alkyl-substituted phenol, said synthetic lubricant being preparedfrom a crystalline paraifln wax having a melting point not greater thanabout 140 F. and a xylene by:

partially chlorinating the parailin wax to form a mixture of chlorinatedwax and unchlorinated wax containing from about 21 per cent to about 24per cent chlorine; mixing the chlorinated wax and unchlorinated wax withsaid xylene in the proportion of at least onemole of xylene to each atomof chlorine in the chlorinated wax mixture; adding a Friedel-Craftscatalyst thereto; heating the mixture thus obtained at about 140 C.until substantially all of the chlorinated wax has reacted with saidxylene; and separating the Friedel crafts catalyst, unreacted xylene andunchlorinated wax from the reaction mixture so obtained, to obtain saidsynthetic lubricant.

'l. A lubricant of low pour point comprising a synthetic lubricanthaving incorporated therewith a small amount, sumcient to characterizethe said lubricant with a pour point at least as low as 0 F., of anester of a wax-substituted phenol, said synthetic lubricant beingprepared from a crystalline parailln wax having a melting point notgreater than about 140 F. and a xylene by: partially chlorine-ting theparaflln wax to form a mixture oi! chlorinated wax and unchlorinated waxcontaining from about 21 per cent to about 24 per cent chlorine; mixingthe chlorinated wax and unchlorinated wax with said xylene in theproportion of at least one mole of xylene to each atom of chlorine inthe chlorinated wax mixture: adding a Friedel-Crafts catalyst thereto:heating the mixture thus obtained under refluxing conditions to therefluxing temperature of said xylene until substantially all of thechlorinated wax has reacted with said xylene; and separating theFriedel-Crafts catalyst, unreacted xylene and unchlorinated wax from thereaction mixture so obtained, to obtain said synthetic lubricant.

8. A lubricant of low pour point comprising a synthetic lubricant havingincorporated therewith a small amount, sufllcient to characterize the 75halogenated wax mixture 8 saidlubricantwithapourpoint atleastaslowas 0'It, or tetraPwax phenol phthalate, said synthetic lubricant beingprepared irom a crystalline aradinwaxhavingameltingpointnot greaterthanabout 140' 1". and a xylene by: partiallychlorinatingtheparamnwaxtoiormamlxmre of chlorinated wax andimchlorinated wax containingrromaboutmpercenttoaboutflpercentchiorine;mixingthe chlorinatedwaxand unchlorlnated wax withsaidxylene in the proportion oi at least are mole of xylene to each atom 01'chlorine in the chlorinated wax mixture; adding a Prledel-Crattscatalyst thereto; heating the mixture thus obtained under refluxingconditions to the refluxing temperature of said xylene untilsubstantially all or the chlorinated wax has reacted with said xylene;and separating the Friedel-C'rafts catalyst. unreaoted xylene andunchlorinated wax from the reaction mixture so obtained, to obtain saidsynthetic lubricant.

9. The method of preparing a lubricant having a pour point at least aslow as 0 F. which oomprises: partially halogenating a crystallineparaffln wax having a melting point not greater than about 140 F. toform a mixture of halogenated wax and substantially unhalogenated waxcontaining an amount or halogen corresponding to from about 21 per centto about 24 per cent chlorine: mixing the halogenated wax andwhalegenated wax mixture with a xylene in the proportion of at least onemole of xylene to each atom of halogen in the halogenated wax mixture;adding thereto a catalyst capable of a effecting a Friedel-Craits typecondensation; heating the mixture thus obtained at a Friedel-Craitscondensation temperature until substantially all or the halogenated waxhas reacted with said xylene; separating the Friedel-Craits catalyst.unreacted iwlene and unhalogenated wax from the reaction mixture soobtained; and adding thereto a small amount suilicient to characterizethe said lubricant with a pour point at least as low as 0' F. of anester of an alkyl substituted phenol.

10. The method of preparing a lubricant having a pour point at least aslow as 0 F. which comprises: partially chlorinating a crystallineparafiin wax having a melting point not greater than about140 F. to forma mixture of chlorinated wax and substantially unchiorinated waxcontaining from about 21 per cent to about 24 per cent chlorine; mixingthe chlorinated wax and unchlorinated wax mixture with a xylene in theproportion of at least one mole of xylene to each atom of chlorine inthe chlorinated wax mixture; adding thereto a Friedel-Craits catalyst:heating the mixture thus obtained under refluxing conditions to therefluxing temperature of xylene until substantially all of thechlorinated wax has reacted \with said xylene; separating theFrledel-Craits catalyst, unreacted :wlene and unchlorinated wax from thereaction mixture so obtained; and adding thereto a small amountsufllcient to characterize the said lubricant with a pour point at leastas low as 0' F. of an ester of an alkyl-substltuted phenol.

11. The method of preparing a lubricant having a pour point at least aslow as 0 F. which comcomprises: partially halogenating a crystallineparaflin wax having a melting point not greater than about F. to form amixture of halogenated wax and substantially unhalogenated waxcontaining an amount oi halogen corresponding to from about 21 per centto about 24 per cent chlorine; mixing the halogenated wax and unwith axylene in the proportion of at least one mole of xylene to each atom ofhalogen in the halogenated wax mixture; adding thereto a catalystcapable of effecting a Friedel-Crafts type condensation; heating themixture thus obtained at a Friedel-Crafts conclensation temperatureuntil substantially all of the halogenated wax has reacted with saidxylene; separating the Friedel-Crafts catalyst, unreacted xylene andunhalogenated wax from the reaction mixture so obtained; and addingthereto a small amount sufficient to characterize the said lubricantwith a pour point at least as low as ,0" F. of an ester of analkyl-substituted phenol.

l2. Themethod of preparing a lubricant having a pour point at least aslow as F. which comprises: partially chlorinatlng a crystalline paraifinwax having a melting point not greater than about 140 F. to form amixture of chlorinated wax and substantially unchlorinated waxcontaining from about 21 per cent to about 24 per cent chlo rine; mixingthe chlorinated wax and unchlorinated wax mixture with a, xylene in theproportion of at least one mole of xylene to each atom of chlorine inthe chlorinated wax mixture; adding thereto a Friedel-Crafts catalyst;heating the mixture thus obtained under refluxing conditions to therefluxing temperature of xylene until substantially all of thechlorinated wax has reacted with said xylene; separating the Friedel-Crafts catalyst, unreacted xylene and unchlorinated wax from thereaction mixture so obtained; and adding thereto a small amountsuflicient to characterize the said lubricant with a pour point at leastas low as 0 F. of an ester of an alkyd-substituted phenol.

13. The method of preparing a lubricant having a pour point at least aslow as 0 F., which comprises: partially halogenating a crystallineparaiiin wax having a melting point not greater than about 140 F. toform a mixture of halogenated wax and substantially unhalogenated waxcontaining an amount of halogen corresponding to from about 21 per centto about 24 per cent chlorine; mixing the halogenated wax andunhalogenated wax mixture with a xylene in the proportion ofat least onemole of xylene to each atom of halogen in the halogenated wax mixture;adding thereto a catalyst capable of effecting a Friedel-Crafts typecondensation; heating unreacted xylene and unhalogenated wax from thereaction mixture so obtained; and adding thereto a small amountsuiiicient to characterize the said lubricant with a pour point at leastas low as 0 F. of tetra-wax phenol phthalate.

14. The method of preparing a lubricant having a pour point at least aslow as 0 F. which comprises: partially chlorinating a crystallineparaffine wax having a melting point not greater than about 140 F. toform a mixture of chlorinated wax and substantially unchlorinated waxcontaining from about 21 per cent to about 24' per cent chlorine; mixingthe chlorinated wax and unchlorinated wax mixture with a xylene in theproportion of at least one mole of xylene to each atom of chlorine inthe chlorinated wax mixture; adding thereto a Friedel-Crafts catalyst;heating the mixture thus obtained under refluxing conditions to therefluxing temperature of xylene until substantially all of thechlorinated wax has reacted with said xylene; separating the Friedel-Crafts catalyst, unreacted xylene and unchlorinated wax from thereaction mixture so obtained; and adding thereto a small amountsufiicient to characterize the said lubricant with a pour point at leastas low as 0 F. of tetra-wax phenol phthalate.

ORLAND M. REIFF.

HOWARD D. HARTOUGH.

HARRY J. ANDRESS, JR.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNI'IED'STATES PATENTS Number Name Date 2,339,493 Lieber'et a1 Jan. 18,1944 2,350,571 Schilling June 6, 1944 40 2,297,292 Davis et a1 Sept. 29,1942 2,189,924 Pier et a1 Feb. 13, 1940 2,048,466 Relfi et a1 July 21,1936 FOREIGN PATENTS Number Country Date 491,522 Great Britain Sept. 5,1938 478,972 Great Britain Jan. 27, 1938 the mixture thus obtained at aFriedel-Crafts OTHER REFERENCES The Condensed Chemical Dictionary, ThirdEdition, 1942. Reinhold Publishing Corporation, New York. Page 487.

Certificate of Correction Patent N 0. 2,443,083. June 8, 1948.

ORLAND M. REIFF ET AL.

It is hereby certified that errors appear in the printed specificationof the above numbered patent requiring correction as follows: Column 7,line 24, for chlorine read chloride; line 31, for "same read said; and tat the said Letters Patent should be read with these corrections thereinthat the same may conform to the record of the case in the PatentOffice.

Signed and sealed this 30th day of November, A. D. 1948.

THOMAS F. MURPHY,

Assistant Uommz'ssz'oner 0 f Patents.

